Stress during pregnancy may affect the child’s health

When a pregnant woman experiences severe stress, the risk of premature birth increases. Her child may be more vulnerable to developing heart defects, diabetes and obesity. Researchers are able to identify correlations such as these thanks to comprehensive health registries.

When a Norwegian is diagnosed with cancer, the treating physician reports the patient’s name, personal identity number, address, diagnosis, and treatment plan to the nationwide Cancer Registry of Norway.

Each Nordic country has a corresponding registry for cancer and for a number of other diseases.

Professor Jørn Olsen at Aarhus University and the University of California, Los Angeles (UCLA) heads a NordForsk-funded project that demonstrates the value of the Nordic health registries for revealing new and significant correlations.

The new study wanted to explore if this also holds true for humans. But examining the effects of stress is no simple matter, since some people can become highly stressed in situations that may not affect others.

So the researchers needed to find a sufficiently large group of women who had unambiguously been exposed to acute stress. Looking into the Nordic health registries, they found anonymised information on women who had lost a child or other close family member immediately prior to or during pregnancy. It was also possible to follow the newborns’ health development for up to 30 years.

Stress and health problems

Fortunately, women rarely lose a previous child during pregnancy; the number of such cases within a single Nordic country is statistically too small to show correlations. However, by using health registries in multiple Nordic countries, the researchers were able to collect enough data to draw conclusions.

After three years of study, the project yielded its first finding: If a mother experiences severe stress during pregnancy, the frequency of premature birth increases. The researchers in the project were also able to document a higher incidence of heart defects and diabetes types 1 and 2 in the children, as well as a higher post-puberty obesity incidence. Stress in the early pregnancy was shown to be particularly harmful.

Potentials for further studies

Professor Olsen sees great potential for using the Nordic registries in future research.

He says that is possible to conduct large-scale studies to identify factors that affect the development of cancer, diabetes, cardiovascular disease, mental health disorders, and so on. The Nordic registries also present the opportunity to search for undesirable side effects of medications taken over a long period of time, such as medicines to lower blood pressure or cholesterol.

"We also want to identify the effects of different cancer treatments in the Nordic countries and examine whether some are more successful than others. There are so many possibilities!", says Olsen.